In commonly owned U.S. Pat. No. 4,610,272 a faucet is disclosed having a mixing-valve actuator comprising a valve housing and a valve member movable by a hand lever which is partly accommodated within the housing and operatively connected to the valve member. The hand lever is movable about two axes perpendicular to each other and is provided with an arcuate portion that projects through a slot of a valve cover into the interior of the housing where it is connected to the movable valve member. The arcuate portion has an inner shape that is aligned with the adjacent part of the cover and has a radius extending from a point on one of the axes.
As the lever is rotated about the center axis of the cartridge, on which the cover is normally centered, it control one characteristic of flow through the cartridge, normally mixing ratio and when tipped about a second axis perpendicular to the first axis it controls another characteristic of flow through the cartridge, normally volume. As a rule the cover itself is rotatable on the housing with the lever and is formed with an aperture constituted as a slot centered on a plane including the first axis and perpendicular to the second axis.
The cover is normally a two-piece affair interconnected by a screwthread. It must be carefully assembled and fitted to the housing, and has a tendency to come loose or apart after some use.